On this parts fiche the Circlip (4l0) is the most specified component.
thirty-five components are shown in this Yz450f 2009 34p2 Europe 1h34p-100e1 17 Transmission exploded diagram.
A sample from the products for the 17 Transmission include: O-ring(328,329), Washer, Lock, Gear, 5th Wheel, Washer.